Anyone who has worn glasses can testify to the aggravation caused by glasses which are not shaped properly to start with, or become slightly deformed in use so that they bear down on one side or other of the nose bridge and dig into the flesh, causing considerable discomfort. This problem may be more acute with sun glasses because generally speaking sunglasses are not prescription or custom, but come off a rack, making it is very unlikely that they would precisely fit the user's nose.
Most people also know of the annoyance of glasses and sunglasses slipping down on the nose when the plastic surface of the nose bridge area becomes slippery with sweat and natural body oils. This causes the user to constantly push the glasses back up on the nose.
In addition, some people have a very flat nose bridge which will not touch the frame portion above the nose bridge of ordinary frames. This is very typical of orientals. When orientals are fitted with western-style glasses, or when they purchase western-style sun glasses, often the nose bridge will not touch the frame of the glasses at all, so that the frame rests on their cheeks.
This flat nose characteristic also applies to a majority of children. Young children's nose bridges do not develop until they are older, so in addition to their noses being small, this causes the frames to fit improperly and to rest on the cheeks. This occurs with both children's glasses and just about all adult glasses worn by children.
There is a need, therefore for a combination spacer, slippage preventer and nose bridge protector, both in combination with existing glasses frames manufactured as original equipment, and also as an add-on unit which could be adapted to most or all of the styles of glasses frames on the market of the type which do not have individual pads on the ends of metal stems which straddle the nose bridge and ride on the sides of the nose.